Heat exchangers with bypass valves are already known in the prior art, and examples of these are found in U.S. Pat. Nos. 2,809,810 and 3,877,514 and 4,991,643. These prior art heat exchangers all include a bypass valve in a fluid-flow tube which restrains the fluid to flow both around the tube and through the tube, depending upon the fluid pressure exerted within the tube. Where these bypass arrangements are utilized in the exchanger, it is of concern to construct the tube with the bypass valve operative thereon, and to then assemble the tube, or a number of those tubes, in a complete heat exchanger. That is, the prior art arrangements require detailed and elaborate constructions to achieve the assembly and installation of the tube within the heat exchanger beyond the complexity and difficulties in achieving the arrangement, the prior art requires a relatively expensive arrangement in both the manufacture of the parts as well as the assembly of the parts within the final assembly of the exchanger tube. Further, to achieve efficiency of cut-off of the fluid flow in the prior art arrangements, they require expensive and precision type of parts and assembly to accomplish the goals.
Accordingly, it is an object of this invention to provide a heat exchanger or oil cooler or the like wherein the fluid-flow tube has a bypass arrangement which is readily and easily provided in the final assembly of the exchanger and which is inexpensive and yet completely reliable and accurate in preventing the flow through the tube, when that is desired, and to subsequently permit flow through the tube, when that feature is desired. Still further, in accomplishing these objectives, the present invention does so with a minimum of parts, and it provides an arrangement wherein the bypass valve is in an assembly which readily attaches to the end of the tube for achieving the cutoff and subsequently achieve the bypass of the fluid, both as desired.
The present invention provides for a heat exchanger which is efficient in the heat exchange function and which provides for relief of excessive fluid pressures. As such, this exchanger or cooler accommodates cold starts and high viscosity fluids in the bypass process when needed, and it therefore also avoids surges in fluid pressure and is more reliable with regard to avoiding leaking, all because of the bypass feature.